Objective shutter



Dec. 16, 1930. R. NERRLICH 4 OBJECTIVE SHUTTER Filed Nov. 21. 1929 2Sheets-Sheet l (d I /zh Dec. 16, 1930. R. NERRLICH OBJECTIVE SHUTTER 2Sheets-Sheet 2 Filed Nov. 21, 1929 Patented Dec. 16; 1930 UNITED STATESPATENT OFFICE RICHARD NERRLICH, OF BERLIN, GERMANY Application filedNovember 21, 1929, Serial No. 408,852, and in Germany November 23, 1928;

lever-like arms connected with one'another.

in known manner by a toggle-joint lever. This known arrangement andcombination of -parts has been improved, according to this invention, asfollows: I

The middle pivot of the toggle lever which projects over the arms ofthis lever at their junction and is guided with this proj'ectmg end in aslot of a sleeve is utilized as a means for damping the shutter halvesat the very last portion of their closing path, the object of thisdamping being the obviation of defective exposures. The object'in viewis attained best by combining with said pivot a piston guided in saidsleeve which forms at its lower end a cylinder in which the quicklydescending piston compresses air at the end' of its path and is therebyquickly, as well as softly, intercepted. 1 The invention is illustrateddiagrammatically and by way of example on the accompanying drawings, onwhich Figure 1 is a .front view of a shutter designed according to thisinvention, only one frame part (of which portions are visible in themiddle parts of Figs. 2 and 3) being omitted in order to show moredistinctly the parts located therebehind; Figure 2 is a similar Viewshowing .some of the movable parts in another position; Figure '3 showscertain of these parts in still another position, and Figure 4 is a vertical section through the middle of the de-.

" vice, all. as fully described hereinafter.

a and a are two semicircular shutting members proper. They are shownclosed in Figs. 1 and 3, and open in Fig. 2 and they are secured to theends of oscillable arms I; and b movably suspended at 0 and 0' at therearv wall at of the shutter frame. The members 5 a and a, as well as band b, are arranged symmetrically with respect to the axis of theobjective and are moved towards, as well as away from, one another bymeans of the arms 6 e of a toggle-joint lever which are connected withthe arms 6 b by means of pivots f f, and with one another by means of apivot g. This pivot is located in a piston k which is guided in a sleevei having at its front face a vertical slot 71 into which extends theforwardly projecting end of the pivot g.

The piston h is laterally slotted, and the inher ends of thetoggle-joint lever arms extend through these slots into the interior ofthe piston where they are connected with this latter and with oneanother by means of the pivot g.

T e tog le-joint lever arms 6 e are subjected to the pull of obliquehelical tensile springs j connected at their upper ends with said armsand at their lower ends with the rear plate of the frame. These springstend continually to hold the arms 6 e in the position shown 'in Fig. 1.When these arms are in this position, the position of the shutters armsI) b is such that the shutter members proper a a are in their shuttingposition, as in Fig. 1.

In front of the shutter arms 6 b is located a lever 1' which isfulcrumed at p to the rear frame plate 01 or, more precisely, to aprojection of said plate so that the lever 1* lies somewhat remote fromthe said plate, viz. just in front of the slotted sleeve 71 which itcrosses below the projecting end of the toggle-joint pivot 9 (Figs. 1and 2).

From the upper end of the sleeve 2' is suspended on a pivot is abell-crank lever consisting of a shorter arm m and alonger arm m. Theshorter arm is designed as a pawl m and the longer arm is connected witha helical tensile spring 0 tending to hold the lever m m in such aposition that the pawl m extends over the slot 11, viz. over the upperend thereof, as in Fig. 2. Normally, however, the springjo is preventedfrom holding said bell-crank lever in said. position, in that the arm mof this lever is subjected to the action, i. e. pressure, of a pin 1-.extending forth forwardly from an. u wardly directed extension forming'a part 0 the lever 1', near 1 the fulcrum p thereof. In the normalposition, or position of rest, of the parts concerned their position isthat shown in Fig. 1 in which the pawl m does not cover the slot 11' ofthe piston guiding member 2'. In this position of the parts the shutteris closed.

When the shutter is to be actuated (for momentary exposure orexposures), the lever r is turned in the direction indicated by thearrow shown at the lefthand side of Fig. 1, whereby the toggle-jointjunction pin or pivot 9 will be lifted, in consequence whereof thetoggle-joint arms 6 6' will be oved asunder, as will also theshutterarms I) b and the shutter members proper a a, the position being thenthat shown in Fig. 2. But this is merely a medium position. While thelever 1' has been turned, as just described. its pin 1'' has at acertain point of its path left the arm m of the bell-crank lever m m andprior thereto the spring 0 has turned this lever so that its pawl m hasfinall arrived over, or in front of, the slot i. ile the lever r isfurther turned upwardly, the position of the toggle-joint lever arms isreversed (Fig. 3) and finally the pin or pivot.

9 contacts with the pawl m and passes along and over it, during whichtime the pawl is first pressed back and then re-assumes automatically(under the pull of the spring 0) its former position, that is to say,that position in which its active portion lies over the slot i. In thismoment the pivot g is locked by the active pawl portion (Fig. 3), and

when now the lever 'ris released or dropped it falls back into a certainmedium position, viz. that in which its in 7" a ain contacts with thearm m of the ell-cran li lever m m, as in Fig. 3. J

While the lever r had been moved from the position Fig. 1 into theposition Fig. 3, the shutting members a a has been opened and closed,and simultaneousl therewith the springs j 9' have been expan ed (Fig.3).

The device is now in its operative position.

for momentary exposure, and the operation for making such an exposure,i. e. the next actuation of the device, consists merely in furtherdepressing the lever 1' so that the pin 1" presses upon the arm m of thebell-crank lever and turns thereby this lever, in conse-' quence whereofthe pawl m will be withdrawn from the pin or pivot 9. Now the expandedsprings 7' can become operative, and they now stretch instantaneouslythe togglejoint lever (position Fig. 2, in which the shutter arms I) bare moved away from one another, as are consequently, also the shuttermembers proper a a) and turn them in the next moment to an angle(position Fig. 1, in which the position of the parts a a and b b is thesame as in Fig. 3). the shutter has been opened a very short time, afraction of a second, and a momentary exposure has been made in thatfraction.

In other words:

- It need hardly be said that together with the toggle joint 'unctionpin or pivot 9 also the iston 6 has een torn downwardly very quic ly bythe springs j, and on the very last portion ofits path it has enteredinto. the damping cylinder 7? whereby the damping intended is attained.The strength of this damping action can, if desired, be regulated byproviding the cylinder 2' with an airescap'e regulating screw, or anyequivalent provision may be made. In every case the shutter membersproper a a are prevented, by the damping, from even the slightestrearward'movement after they have arrived in their end position in whichthe shutter is completely closed, and this being so, defective exposuresare completely prevented.

I claim:

1. An objective shutter of the character described, comprising, incombination, a pair of oscillable arms adapted to be moved towards, andaway from, one another and forming at their free ends the shuttingmembers proper for the objective; a toggle-joint lever located betweensaid arms and being connected with them; springs engaging thetoggle-joint lever arms and tending to maintain said shutter membersproper in closed position; a slotted longitudinal member also locatedbetween the oscillable arms and behind said toggle-joint lever, themiddle junction pivot of this lever engaging said slot; and dampingmeans so arranged as to be adapted to intercept the said shutter membersproper just before the very end of their closing path.

2. An objective shutter of the character described, comprising, incombination, a air of oscillable arms adapted to be move towards, andaway from, one another and forming at their free ends the shuttingmembers proper for the objective; a toggle-j oint lever located betweensaid arms and bein connected with them; springs engagingt e togglejointlever arms and tending to maintain said shutter members proper in closedposition' a slotted longitudinal member also located between theoscillable arms and behind said toggle-joint lever, the middle junctionpivot of this lever engaging said slot; and means so arranged withrespect to said pivot as to intercept it'just before the end of itsdownward path and to stop thereby elastically also the other movablemembers connected with it directly and indirectly, substantially as setforth.

3. An objective shutter of the character described, comprising, incombination, a pair of oscillable arms adapted to be moved towards, andaway from, one another and forming at their free ends the shuttingmembers proper for the objective; a toggle-joint lever located betweensaid arms and being connected with them; springs engaging thetoggle-joint lever lib arms and tending to maintain said shutter membersproper in closed position, the lowermost portion of this member beingdesigned as a cylinder, and the said member being also located betweenthe oscillable arms and behind said toggle-joint lever, the

middle junction pivot of this lever engaging said slot; a piston locatedin the slotted longitudinal member and being connected with said pivot,this latter being adapted to damp elastically the movable' membersconnected directly and indirectly with it just prior to said shuttingmembers proper arriving in their closed position.

4. An objective shutter of the character described. comprising, incombination, a pair of oscillable arms adapted to be moved towards, andaway from, one another; semicircular shutting members proper attached tothe free ends of said arms; a toggle-joint lever located between thesaid arms and being connected with them; springs engaging saidtoggle-joint lever and tending to keep said shutting member proper inclosed position; a sleeve arranged between the osc'illable arms behindsaid toggle-joint lever and having a longitudinal slot receiving themiddle junction pivot of the toggle-joint lever arms and guidingdirectly said pivot and the movable parts connected therewith; apiston-like member arranged within said sleeve and being connected withthe said pivot and adapted to be moved upwardly and downwardly in thesaid sleeve in correspondence with the,

toggle-joint lever arms and the-parts connected with them; a cylinderconstituting the lowermostend of the said sleeve and forming a dampingspace for said piston when this latter arrives at the very end of itspath, substantially as set forth.

5. An bjective shutter of the character described, comprising, incombination, two

practically parallel one-armed levers terminatin at the objective;semi-circular objective s utting members attached to the ends ofsaidlevers and forming together the shutter proper for the objective; asleeve arranged between said levers practically parallel to them andhaving a slot at its front face and forming a cylinder at that end whichis located near the objective; a piston arranged in said sleeve;toggle-j oint lever arms arranged in front of said slot and beingconnectedwith the middle junction-pin of the toggle-joint lever; andsprings engaging the toggle-joint lever arms and tending to turn them soas to keep the shutter proper closed,

substantially as set forth.

In testimonymhereof I aflix my signature.

' RICHARD NERRLICH.

